Chronic urticaria (CU) is a skin disorder that affects an estimated 20% of the Western population at some point in their life (1).

The characteristic red and white urticaria hives of the disorder can be caused by allergies, infections or reactions to physical factors such as cold, humidity, sunlight or pressure (1).

However, often it is not possible to identify the exogenous triggering factor, and if the disease persists for more than 6 weeks, these patients are diagnosed as having chronic spontaneous urticaria (CSU) (2).

IGE/FCERI AUTO-ANTIBODIES IN CHRONIC SPONTANEOUS URTICARIA

In the literature 30-60% of the CSU patients are reported to have circulating IgG auto-antibodies against the alpha chain of the high affinity IgE-receptor (FcεRI) or more rarely against IgE itself, when investigated with antibody binding tests such as immunoblot or ELISA (3).

These tests have nevertheless been reported to frequently test positive in healthy subjects, in patients with other forms of urticaria and such diverse dermatological conditions as atopic dermatitis, dermatomyositis and angio-oedema (2,3).

Thus, the mere presence of auto-antibodies does not necessarily indicate that these antibodies are also functional, and on this background it is necessary to demonstrate functionality of the IgE/FcεRI auto-antibodies in order to verify that the CSU is truly of autoimmune origin, as non-functional auto-antibodies have also been observed in CSU patients (3).